In general, diversity gain is defined as the increase of the receiver sensitivity in a given propagation scenario over the reception without diversity.
It is already known, in the context of radio systems in analog and digital technology, that an improvement of the sensitivity of a receiver system can be effected by using a plurality of antennas (in general two).
In conventional radio transmission applications, antenna diversity schemes are preferably employed in order to reduce fading effects (fluctuations of the receiver field strength during radio transmissions).
An exactly defined and precisely quantifiable determination of the diversity gain (DG) that would allow additional system parameters, such as for example the required transmission power of a station, to be derived therefrom and optimized for design purposes, however, has thus far not been satisfactorily established.
According to the prior art the diversity gain (DG) is expressed statically (for a fixedly defined connection distance) with a defined antenna configuration. This information is inadequate for many applications, such as for example in mobile radio communications.
A precise definition of the diversity gain (DG) is therefore needed. One proposal for determining or measuring the diversity gain (DG) in the case of portable terminals is disclosed in the publication by Tsunekawa (Spatial, Polarisation, and Pattern Diversity for Wireless Handheld Terminals).
In this case the diversity gain (DG) is determined by means of the S/N improvement and the correlation factor of the signals delivered by two antennas. The measurement of both values is very problematic, lengthy, and imprecise [comparison of measurement with theory, see Tsukenawa FIG. 8-4 (d)].
DE 197 27 516 A1 discloses a method for the determination of the internal static noise of digital circuits, wherein the relationship log (BER)=f(Pe) with C/I as a parameter is used, which relationship is also used in the context of the method described below, where parallel straight lines are also calculated by means of interpolation of neighboring straight lines.
U.S. Pat. No. 5,812,539 A and US 2004/104844 A1 disclose (diversity-) receiver systems and the application of interpolated/extrapolated values, wherein the input power at the receiver system is reduced in order to thereby produce a diversity gain.
The problem addressed by the present invention is therefore considered that of providing a method that supplies, for a certain radio transmission system (e.g. UMTS, B3G, WLAN), a defined diversity gain (DG) value quickly and with high accuracy for development and design purposes.